Field Blast Tests Research Articles

Dynamic behavior of concrete filled steel tubular columns internally strengthened with I-shaped CFRP against vehicular bombs

Square concrete filled steel tubular columns internally strengthened with I-shaped carbon fiber reinforced polymer (SCFST-CFRP) demonstrate promising potential for application in building structures, particularly in high-risk buildings and critical structural elements, due to their exceptional static and impact resistance. High-risk buildings may be vulnerable to vehicular bomb attacks over their lifespan, resulting in blast loading. In this study, the blast resistance of SCFST-CFRP columns is investigated through field blast tests and numerical simulation. The plastic deformation of SCFST-CFRP members is low, and they exhibit promising blast resistance in explosion tests with a scaled distance of 0.07 m/kg1/3. Subsequently, SCFST-CFRP columns with varying steel ratios were designed according to specifications to investigate their deformation and damage under typical vehicular bomb scenarios. It was found that the blast resistance of SCFST-CFRP columns is superior to that of ordinary SCFST columns, particularly when the steel ratio is smaller. Additionally, a protection distance of 3.95 m (1.01H) is sufficient to ensure that the composite columns do not fail under these scenarios, highlighting favorable blast resistance for SCFST-CFRP columns. Based on the parametric analysis of 115 sets of data, a prediction formula for the critical failure distance of SCFST-CFRP columns under typical vehicular bomb scenarios is proposed. This study serves as a valuable reference for designing SCFST-CFRP columns with blast resistance.

Structural safety and failure analysis of buried jointed high-density polyethylene corrugated pipelines subjected to blast vibration

The reliability of buried jointed high-density polyethylene (HDPE) corrugated pipelines under urban blast vibration loading needs to be emphasized. This study combines field blasting tests on directly buried single-section pipelines and numerical simulations to investigate the mechanical performance of jointed HDPE corrugated pipelines under complex blasting conditions. Intelligent prediction models based on genetic algorithm (GA), particle swarm optimization (PSO), and white shark optimization (WSO) combined with extreme learning machine (ELM) are proposed, namely GA-ELM, PSO-ELM, and WSO-ELM models, respectively. The numerical model is established using the orthogonal experimental principle to supplement the predicted sample data. By comparing the predictions of RPPV (resultant peak particle velocity) and RPPD (resultant peak particle displacement) for the pipelines under various working conditions using the four optimized ELM models, the results indicate that the WSO-ELM model is the best intelligent model for predicting the pipeline response characteristics. By combining the pipeline deflection criterion with the WSO-ELM prediction model, adjustments to the field blast parameters can be made to ensure the safety of the pipeline while improving construction efficiency.

Numerical and analytical studies of multi-cell steel-concrete-steel sandwich panels under blast load

The steel-concrete-steel (SCS) sandwich panel possesses exceptional resistance and good integrity, making it successfully applied in protective engineering. Aiming at improving the blast resistance of the structure, a novel multi-cell steel-concrete-steel (MCSCS) sandwich panel was proposed as an alternative to the traditional SCS panel. In this paper, the finite element (FE) model of the MCSCS panel under blast load was first constructed, and the modeling method was verified to be reasonable against field blast tests. Then, an analytical model for predicting the blast response of the MCSCS panel was established based on the equivalent single-degree-of-freedom (SDOF) system, and the strain rate effect was incorporated into the analytical model via employing the material models with strain rate dependence. Finally, three damage criteria for the MCSCS panel under blast load were proposed, and Pressure-Impulse (P-I) diagrams corresponding to different damage levels were constructed via the validated analytical model. Additionally, based on the established analytical model, the accuracy of simplifying the blast pressure history into the triangle form was verified. Numerical and analytical results indicate that the blast resistance of the MCSCS panel is significantly enhanced with the increase of the steel faceplate thickness, and the MCSCS panel exhibits superior blast resistance with the load acting on the top plate rather than bottom plate. In addition, owing to the arrangement of the L-shaped and side stiffeners, the MCSCS panel possesses preferable integrity, and its blast resistance is nearly unaffected by the spacing of headed stud.

Blast mitigation effects of TPU polymers-based inflated membrane structures under external explosion

TPU polymers-based inflated membrane structures are a potential technology to protect pre-existing lightweight buildings, with the advantages of lightweight and simple building process. In this study, a series of field blast tests were performed for the structural response and blast load parameters to study the blast mitigation effect of the inflated membrane structures. The corresponding numerical models of the tests were then developed and validated to reproduce the fluid-structure interaction. Thin aluminum plates were used as the protected structure. Based on their maximum displacement, average plastic strain, depth of depression, and permanent deformation, damage factor was defined to evaluate their damage level. Both the experimental and numerical results show that inflated membrane structures can effectively mitigate blast loading and significantly reduce the permanent displacement of the aluminum plate by elastic compression deformation. The effects of the initial height and internal pressure of inflated membrane structures on the blast mitigation effectiveness were clarified by the parametric study. The overpressure-impulse equivalent damage curves were established by combining the damage factor and overpressure-impulse loads, which further confirmed the blast mitigation performance of inflated membrane structures. Our study has verified the blast mitigation effects of inflated membrane structures based on TPU polymers, which is potentially valuable in the field of protective engineering for lightweight construction.

The destructive form and response analysis of buried concrete pipes under the action of internal explosion loads

This research analyzes the damage mechanism of subterranean concrete pipelines subjected to internal explosive loads using a mix of field blasting tests and numerical simulations. The field tests reveal that, under the effect of internal explosion loads, axial and circumferential cracks occur in the concrete pipelines, with the crown, invert, and springline being damaged firstly, leading to penetrating cracks. In addition, an arbitrary Lagrangian Euler (ALE) method is used to establish a coupled model of underground concrete pipeline under the condition of internal explosion. The influence of the explosion mass on the destructive effects and dynamic characteristics of the pipeline is investigated, and the internal wall strain at the explosion center and in the central part of the pipeline is analyzed. Furthermore, the propagation and attenuation laws of shock waves in pipelines are investigated, and an attenuation law formula of shock waves inside the pipeline with two ends open is provided, which will be useful for future research.

Research on internal explosion loads in folded arch tunnels: A theoretical approach

To elucidate the loading characteristics in the folded arch tunnel subjected to internal explosion, a field blast test was conducted in a large-scale (1:5) model constructed according to the immersed tube tunnel of Hong Kong-Zhuhai-Macao Bridge. The spatial distribution and time histories of the overpressure around the detonation point were recorded in the folded arch tunnel. The test data indicate that the internal blast loads in the folded arch tunnel is mainly attributed to the shock overpressure and gas overpressure. A fine FE model was developed in the LSDYNA platform, which was validated by the loading test data. The propagation process of blast waves and detonation products along the folded arch tunnel were studied by the developed model, which also helped reveal the interaction mechanism with the tunnel structure. Three existing theoretical models in predicting the internal blast loads were compared and assessed. It is found that the existing theoretical models developed for the internal blast loads has limitations in predicting the blast load in the tunnel, which especially would introduce a large error in manifesting the gas overpressure. A new loading model that enables precisely predicting the internal blast loads in the folded arch tunnel was proposed, which offers valuable insights for the blast-resistant design and disaster mitigation measures for the tunnel structure.

Stone Mastic Asphalt Modified With Nano Titanium Dioxide And Potential Exposure To Blast Load: A Review

This article states the modification of stone mastic asphalt with nano titanium dioxide and the advantage it has over conventional asphalt. The transport infrastructures must meet the needs of transport as well as other requirements like resilience and multi-hazard resistance in order to satisfy society's desire for sustainable development. Hence, blast load is introduced in this paper as one of the potential hazards that may be exposed to pavements. The use of SMA with nano titanium is believed to impact the pavement's behaviours significantly and can potentially resist higher blast loads and reduce failure in samples. As real field blast tests are limited, a numerical analysis is done to assess the modified pavement's enhancement. The article concludes by recommending using SMA modified with nano titanium as a promising solution to withstand blast loads in pavements.

A theoretical method for scaling the dynamic response of steel beams subjected to blast loads

Conducting experiments using scaled models is a highly efficient and cost-effective approach to predicting structural dynamic responses to blast loads. However, accurate representation of the prototype in a scaled model is hindered by the strain rate effect of the materials, thus limiting the application of scaled model tests. To address this issue, this paper proposes a theoretical correction method for scaling the dynamic response of steel beams subjected to blast loads. This method allows for direct and quantitative evaluation of the error caused by the strain rate effect on the similarity of the maximum mid-span displacement of the beam without the need to modify the charge mass or stand-off distance. In addition, the proposed method eliminates the need for extensive model tests. The accuracy of the proposed method is verified through numerical simulations. The results demonstrate that the strain rate effect scarcely influences the geometric similarity of the maximum mid-span displacement of the beam in the elastic response stage. However, in the plastic response stage, the maximum mid-span displacement of the beam does not conform to geometric similarity. Accordingly, the similarity of the maximum mid-span displacement of the beam can be expressed as the product of the geometric scale factor and calculated strain rate correction coefficient. These theoretical innovations can significantly enhance the reliability of scaled-model tests, help extrapolate scaled-model test results back to the prototype, and reduce the difficulty and consumption of field blast tests.

The experimental and theoretical study on the spatial‐temporal distribution of electromagnetic radiation from JO‐8 explosions.

AbstractThe detonating fuse in the multistage warhead will be subjected to strong electromagnetic interference, derived from electromagnetic radiation generated by explosion of the shaped charge warhead, which may cause premature detonation or misfire. In order to explore the possible electromagnetic environment surrounded the detonating fuse, the spatial‐temporal distribution of electromagnetic radiation after the explosion of JO‐8 explosive was investigated in this paper. The electromagnetic radiation signal was collected and its frequency coverage was analyzed in the far‐field area by the field blast test. Moreover, based on electromagnetic theory, a theoretical model of electromagnetic radiation generated by the explosion of JO‐8 explosive was established, and the spatial‐temporal distribution of the electric field intensity was illustrated in detail for several typical positions after the explosion. The better agreement between experimental and theoretical results indicates that the proposed theoretical model and computational method are reasonable. On this basis, the distributions of electric field intensity for different positions and various explosive weights were predicted respectively by using distance and explosive weight as variables. This study is expected to provide a reference for the research on the electromagnetic radiation for explosive explosion and anti‐explosive electromagnetic interference.

Dynamic Response Mechanism of Thin-Walled Plate under Confined and Unconfined Blast Loads

Thin-walled metal plates and cabin structures are widely found in ships and cargos which are susceptible to attacks or accidental explosions. The present work focuses on the dynamic response mechanism of steel plates under unconfined and confined blast loads. In the experiment, digital image correlation (DIC) technique was applied to record and analyze the dynamic response process of a large-scale field blast test. The DIC measured curve and the numerically calculated curves agree well in both trends and peak values. Then, the dynamic response mechanisms of steel plates under an unconfined blast (UB) load and confined blast (CB) load were compared and discussed. The results show that the dynamic response of plates can be divided into three phases under both UB and CB loads, with different mechanisms. In phase I, plastic hinges start from the center and move to the boundary in the UB condition, while in the case of CB, plastic hinges occur close to the boundary and move in the opposite direction. In phase II, two plastic hinge lines propagate towards each other, a platform exists between the boundary, and the central area remains undeformed in the UB condition, while in the CB condition, larger deformation occurs in the peripheral region rather than the central area.

Strength prediction and stochastic analysis of ultra-high performance concrete columns under the explosive blast load

The performance research based on numerical and experimental studies on ultra-high performance concrete (UHPC) generally considers it as an isotropic material, which is obviously different from what it really is in practical engineering. A database of UHPC compressive strength was investigated, having the same UHPC mix proportion as the field blast experiment, to show how the strength of UHPC varies in compression. It is found that Weibull distribution is the best fit of its probability model. A combination of Monte-Carlo and Finite Element method is used, adopting the available UHPC compressive strength, to reproduce the field blast test on UHPC columns. Both the non-spatial and spatial variability of material properties of the UHPC columns are under consideration to conduct the UHPC column strength prediction under blast loads. The residual loading capacity, damage index and failure mode of UHPC columns with different sizes damaged by different explosion severities are obtained by non-spatial simulation and spatial simulation respectively. It can be concluded that compared with the non-spatial model, the numerical simulation results of the spatial model are closer to the experimental situation. Therefore, inclusion of spatial variability is recommended for reliability-based blast-resistant design for UHPC column.

Investigation on overbreak and underbreak of pre-stressed tunnels under the impact of decoupled charge blasting

Decoupled charge blasting has shown its superior performance in achieving smooth tunnel profiles in underground excavation. In this study, through establishing an underground tunnel blasting similarity modeling (UTBSM) test system that incorporates a static stress loading device (SSL), a highspeed digital image correlation device (DIC) and a 3D laser scanning device (3DLS), field blast tests with concrete models involving set-aside circular and rectangular openings are first conducted to examine the influence of filling medium on the depth and area of overbreak and underbreak. Subsequently, a 3D finite element model is developed using LS-DYNA and validated against one of the test results, and the influences of decoupled coefficient, decoupled charge mode, filling medium, and in-situ stress condition are comprehensively investigated. Finally, an energy analysis encompassing internal energy and kinetic energy is performed. The experimental and numerical results show that water-decoupled blasting results in the largest overbreak and smallest underbreak due to the highest internal energy and kinetic energy, and the expanded polystyrene foam (EPS) effectively reduces the blasting energy exerted on concrete so that causes the minimum overbreak depth and volume. Both the overbreak and damage in burden decrease with increasing decoupled coefficient. Radial decoupled charge mode produces a higher energy transfer efficiency than axial charge mode, whereas eccentric charge mode outperforms in controlling overbreak and improving the excavation efficiency. Additionally, the increase of in-situ stress leads to a reduction in overbreak depth and damage volume in the burden, indicating that in-situ stress plays a favorable role in overbreak control during contour blasting. However, the restraining effect of in-situ stress on rock fracture warrants sufficient attention as it may result in blasting failure.

Structural behavior of steel-concrete-steel and steel-ultra-high-performance-concrete-steel composite panels subjected to near-field blast load

In this paper, field blast tests and numerical simulations were conducted to investigate the structural behavior of steel-concrete-steel (SCS) composite panels with shear studs and tie bars as connectors under near-field blast load. Four specimens, including two SCS panels, one steel-ultra-high-performance-concrete-steel (S-UHPC-S) and one normal reinforced concrete (NRC) panel, were fabricated with the same geometric dimensions and tested in the field with cylinder charges under the scaled distances of 0.4 m/kg1/3 and 0.6 m/kg1/3. Finite element models with the implementation of multi-material Arbitary-Lagrangian-Eulerian (MM-ALE) algorithm were built to demonstrate the spatial distribution of shock waves with adequate validation, and the calculated blast load was then simplified and used to compute the dynamic response and the failure mode of SCS and S-UHPC-S panels. After validation of the numerical models, the parametric studies were conducted to investigate the effects of thickness and yield strength of faceplates, ratio of shear connector spacing to the faceplate thickness, section depth of the panels and scaled distance on the structural behavior of SCS and S-UHPC-S panels against near-field blast load. The results indicate that the structural response of SCS and S-UHPC-S panels under the near-field blast load is dominated by global flexural response with the scaled distance (Z) ranging from 0.3 m/kg1/3 to 0.6 m/kg1/3, but shear cracks form near the supports and local damage occurs at Z = 0.3 m/kg1/3. Replacing normal concrete core with UHPC or enlarging the section depth is an effective way to mitigate shear cracking and potential shear failure. In addition, the blast resistance of SCS panel is much superior to that of NRC panel with the same geometric dimensions and is also much greater than that of NRC panel with the similar section strength under close-in scaled distance.

Experimental study on the residual seismic performance of CFDST columns after contact explosion

Bridge columns are susceptible to various hazards throughout their service life, including accidental explosions, terrorist bombing attacks, and earthquakes. To support engineers and owners in making informed decisions regarding post-blast maintenance strategies for damaged bridges, it is crucial to gain a thorough understanding of the residual performance of affected bridge columns following the aforementioned incidents. This paper aims to investigate the residual seismic performance of concrete-filled double-skin steel tube (CFDST) columns through experimental means after being exposed to blast loading. The study consists of two phases: a field blast test and a quasi-static cyclic test, both conducted to evaluate the residual seismic performance of CFDST columns. Two circular column specimens and two square column specimens, each with similar nominal axial load-carrying capacities, were constructed and tested. One circular and one square column were initially subjected to a contact explosion before undergoing lateral cyclic loading. The remaining two columns were directly tested under cyclic loading to examine their seismic performance in an undamaged condition. By comparing the test results of the blast-damaged columns with those of the intact columns, the residual seismic performance of the blast-damaged columns is evaluated. The results indicate that the blast-damaged columns retain satisfactory lateral strength, stiffness, ductility, and energy dissipation capacity, highlighting the resilient performance of CFDST columns in a post-blast earthquake scenario. Furthermore, it was observed that the residual seismic performance of blast-damaged columns is more affected in the loading direction towards the side of blast damage. A residual index of energy absorption capacity is proposed to quantify the residual seismic capacity of blast-damaged CFDST columns. The results demonstrate that circular column exhibits better blast resistance and residual seismic performance compared to the square column. This study contributes valuable insights for the application of CFDST columns in multi-hazard scenarios involving potential contact explosions in seismic regions.

Experimental and numerical study on ground shock propagation in calcareous sand

Surface explosion tests were conducted on calcareous sands to study the ground shock propagation in this medium. In the tests, ground shock at scaled distances between 0.33 m/kg1/3 and 1.46 m/kg1/3 was measured. After each explosion, the surface craters were observed and measured. The propagation and attenuation law of the peak pressure was derived according to the experimental measurement. The shock wave velocity and rise time were derived based on the pressure time-history curves. The empirical formula for pressure time-history curve of direct ground shock in calcareous sand induced by surface explosion was derived, and the predicted impulses showed good agreement with the experimental impulses. The indirect ground shock induced by air shock compression effect on the soil was discussed. Based on the field blast test results, validated numerical models were established to investigate the propagation of direct and indirect ground shock in calcareous sand. The attenuation law of peak pressure of indirect ground shock was then derived according to the numerical simulation results. Besides the surface explosion scenario, the contained burst cases were also modelled. The critical scaled depth of burial was derived as 1.3 m/kg1/3 in calcareous sand based on the surface crater and shock impulse.

Improving blast protection of double-layered system for infilled masonry wall in frame structure

To dissipate a large amount of blast energy as well as realize a reasonable load transfer to the beam and column instead of the vulnerable wall in the frame structure, this study employs a novel double-layered system to protect the infilled vulnerable masonry wall to resist blast loads. The system comprises a sacrificial cladding directly exposed to the blast to dissipate energy and connectors to facilitate load transfer and mitigation. Based on the quasi-static compressive test on the connector, the field blast test on the sacrificial cladding and frame structure with an infilled masonry wall, their respective numerical models are established and validated with ANSYS/LS-DYNA, which facilitates the model establishment of the frame structure protected by the double-layered system subjected to blast load. The numerical results indicate that the system effectively mitigates the damage to the masonry wall and reduces the load transferred to the frame compared to that without protection. However, large bending deformation of the sacrificial cladding may still result in collision damage to the vulnerable wall which makes it difficult to be applied in engineering practice. To improve the protective performance of the double-layered system and reduce the possibility of the occurrence of a collision between the sacrificial cladding and the wall, several measures, including connector layout optimization, rear plate strengthening with stiffeners, and appropriate connector height determination have been proposed. The numerical results demonstrate that installing connectors at four edges, adding 5 × 5 stiffeners on the rear surface of the sacrificial cladding, and appropriately designing the height of the connector can significantly enhance the double-layered system’s protective performance, which has practical significance in protecting vulnerable masonry wall in frame structure from blast loads.

Blast test and probabilistic vulnerability assessment of a shallow buried RC tunnel considering uncertainty

The purpose of this investigation is to analyze the failure probability of a blast in a shallow RC tunnel. The field blast tests are carried out, and a refined finite element model (FEM) is established based on LS-DYNA. To account for blast uncertainty, the Monte Carlo method is used to determine 150 blast conditions. A failure evaluation method based on a mechanical performance index is proposed. The probabilistic blast demand model (PBDM) and the probabilistic blast capacity model (PBCM) are established. Finally, a probability assessment framework based on the structural performance index and the vulnerability curve for shallow tunnels are established. According to the findings, when the mass of TNT in the tunnel exceeds 300 kg, the tunnel is in danger of collapsing. At this moment, it is suggested that people enter the tunnel cautiously. The vulnerability curve predicts the failure probability of a tunnel under various blast loads. At the same time, it could assess its structural performance after the disaster.

Failure modes and dynamic responses of roller compacted concrete gravity dams subjected to underwater contact explosion based on the cohesive model

Considering the construction technology of roller compacted concrete (RCC) gravity dams, there are layers in dams inevitably, which may affect the blast responses of dams. This paper is aimed to investigate the effects of RCC layers on the failure modes and dynamic responses of RCC gravity dams bearing underwater contact explosion loading. Initially, the zero-thickness cohesive element model is presented to simulate the crack behavior of the RCC layers. An impact test of a concrete beam is selected to verify its reliability. The concrete damage plasticity model considering strain rate effects is utilized to simulate the various responses of concrete under blast load. The dam–reservoir–foundation interactions are described using the coupled Eulerian-Lagrangian method. The numerical methods are validated by a field blast test of a concrete structure. Subsequently, numerical models were established for gravity dam-reservoir-foundation systems, with and without considering RCC layers respectively. Based on validated algorithms, these models were utilized to explore the effects of RCC layers on the blast performance of the dam. Finally, the influence of the parameters of RCC layers on the nonlinear responses and failure modes of the dam is further investigated, including the maximum traction, the fracture energy, and the layer thickness. The results reveal that the layers significantly change the failure modes. The RCC layers are the weak link of the dam and they will lower the anti-explosion performance of the dam. Therefore, it is crucial to take the layers into account when conducting anti-explosion research, and RCC dams cannot be simply simplified as normal concrete dams. To guarantee the safety of the dam, it is important to ensure the layers with sufficient strength and fracture energy, as well as an appropriate thickness.

A case study of blasting vibration attenuation based on wave component characteristics

A typical blasting vibration wave is a composite wave, and its attenuation law is affected by the type of dominant wave component. The purpose of the present study is to establish an attenuation equation of the peak particle velocity (PPV), taking into account the attenuation characteristics of P-, S- and R-waves in the blasting vibration wave. Field blasting tests were carried out as a case to specifically apply the proposed equation. In view of the fact that the discrete properties of rock mass will inevitably cause the uncertainty of blasting vibration, we also carried out a probability analysis of PPV uncertainty, and introduced the concept of reliability to evaluate blasting vibration. The results showed that the established attenuation equation had a higher prediction accuracy, and can be considered as a promising equation implemented on more complex sites. The adopted uncertainty analysis method can comprehensively take account of the attenuation law of blasting vibration measured on site and discrete properties of rock masses. The obtained distribution of the PPV uncertainty factor can quantitatively evaluate the reliability of blasting vibration, which is a powerful and necessary supplement to the PPV attenuation equation. • The dominant wave component type affected the attenuation law of blasting vibration. • A PPV attenuation equation considering the wave components was established. • A field blasting test verified the feasibility of the proposed equation. • An uncertainty probability analysis method of blasting vibration was proposed. • Both lithological parameters and vibration law were considered in the method.

Blast fragility assessment of aging coastal RC columns exposed to non-uniform CIC attacks using LBE function

Along the service period of aging coastal reinforced concrete (RC) structures, chloride-induced corrosion (CIC) is a major cause affecting their life-cycle performance and durability. RC columns are the important vertical members of many long-span highway bridges and high-rise buildings, and they are vulnerable to the deterioration effects caused by non-uniform CIC and the intentional terror activities or accidental explosive attacks. The catastrophic failure of RC columns could trigger the progressive collapse of buildings and bridges, leading to huge economic losses and casualties. Very few studies have investigated the time-dependent blast fragilities of deteriorating coastal RC columns exposed to non-uniform CIC. To this end, we proposed an integrated time-dependent blast fragility assessment framework for aging coastal RC columns, considering the deterioration effects caused by non-uniform CIC in marine conditions. Firstly, a three-phase time-variant deterioration rate model for steel bars that considers the accelerated increase of the steel corrosion rate after the cover concrete cracking was incorporated in the analytical modeling of non-uniform CIC of aging RC structures. Secondly, Load-Blast-Enhanced (LBE) function in LS-DYNA was implemented to numerically simulate blast loads, and the effectiveness of the numerical models was validated by the available field blast test results reported in the literature. Subsequently, the performance damage states (e.g., low, medium, and high) of RC columns under intensive blast loads were defined in terms of the damage degree index (D) by using the LBE method, and the pressure-impulse (P–I) models were constructed accordingly. Finally, by using the scaled distance (Z) as the blast loading intensity measure (IM), Monte Carlo Simulations (MCS) were used to conduct the blast fragility analysis for a typical aging coastal RC column. The proposed time-dependent blast fragility assessment framework for aging RC columns is demonstrated to be appropriate and effective in evaluating their deteriorated blast loading-resistance, and it is also a good candidate to estimate the time-dependent blast fragilities of deteriorating coastal RC columns.